#!/usr/bin/env python3
"""test_moon_composite.py — smoke-test the east-sky-backdrop composite.

Uses the sample east frame (21-07-00.jpg) already in the repo and a
procedurally generated moon disc (no camera timestamp, no copyright) to
demonstrate the east-sky backdrop without needing a live NASA API call.

Run from the sky-cam directory:

  python3 test_moon_composite.py

Output: test_composite_out.jpg

The east frame (2026-04-29 21:06:45) shows the moon through visible thin
cloud cover; that sky — blurred to atmospheric haze — becomes the backdrop
behind the procedural moon disc.  In production the disc is replaced by the
NASA SVS Dial-a-Moon render for the exact UTC hour east captured the moon.
"""

import pathlib
import sys
from datetime import datetime, timezone

HERE = pathlib.Path(__file__).resolve().parent
sys.path.insert(0, str(HERE))

EAST_FRAME = HERE / '21-07-00.jpg'
OUT_PATH   = HERE / 'test_composite_out.jpg'


def _make_procedural_moon(size: int = 2048) -> 'Image':
    """Generate a clean grey disc that stands in for a NASA Dial-a-Moon render.

    Draws a base disc, a few darker ellipses for lunar maria, and a subtle
    limb-darkening gradient.  No timestamp, no copyright, no camera artefacts.
    """
    from PIL import Image, ImageDraw, ImageFilter
    img = Image.new('RGB', (size, size), (0, 0, 0))
    draw = ImageDraw.Draw(img)

    cx = cy = size // 2
    r = int(size * 0.47)

    # Base disc — warm grey, slightly off-white like a real moon
    draw.ellipse([cx - r, cy - r, cx + r, cy + r], fill=(218, 214, 200))

    # A few darker patches suggesting the major maria
    draw.ellipse([cx - r//3,  cy - r//3,  cx + r//6,  cy + r//5],  fill=(170, 167, 154))
    draw.ellipse([cx + r//8,  cy - r//5,  cx + r//3,  cy + r//8],  fill=(182, 179, 166))
    draw.ellipse([cx - r//4,  cy + r//6,  cx + r//8,  cy + r//3],  fill=(175, 172, 159))
    draw.ellipse([cx - r//2,  cy - r//10, cx - r//5,  cy + r//4],  fill=(185, 182, 169))

    # Smooth the hard edges so it blends naturally
    img = img.filter(ImageFilter.GaussianBlur(radius=size // 80))

    # Subtle limb darkening: blend a radial dark vignette at the disc edge
    vignette = Image.new('L', (size, size), 0)
    vd = ImageDraw.Draw(vignette)
    vd.ellipse([cx - r, cy - r, cx + r, cy + r], fill=255)
    vignette = vignette.filter(ImageFilter.GaussianBlur(radius=size // 30))
    import numpy as np
    arr  = np.asarray(img).astype(float)
    vig  = np.asarray(vignette).astype(float) / 255.0
    # Darken towards the limb (where vig is small → near edge)
    darken = 0.75 + 0.25 * vig          # 0.75 at edge, 1.0 at centre
    arr = np.clip(arr * darken[..., None], 0, 255).astype('uint8')
    img = Image.fromarray(arr)

    return img


def main():
    if not EAST_FRAME.exists():
        print(f'ERROR: missing {EAST_FRAME}', file=sys.stderr)
        sys.exit(1)

    # Save the procedural disc to a temp file so render_phase_closeup can open it
    import tempfile, os
    with tempfile.NamedTemporaryFile(suffix='.png', delete=False) as tf:
        tmp_moon = tf.name

    try:
        print('=== moon composite smoke-test ===')
        print(f'east frame : {EAST_FRAME.name}')
        print(f'moon disc  : procedural (NASA Dial-a-Moon stand-in)')
        print(f'output     : {OUT_PATH.name}')
        print()

        print('generating procedural moon disc …')
        moon_img = _make_procedural_moon(2048)
        moon_img.save(tmp_moon)

        from moon_composite import render_phase_closeup
        caption = (
            'Full Moon — April 2026 — '
            'sky-cam east witnessed at 2026-04-29 21:07:00 UTC '
            '(+7 min from exact full) — render: NASA SVS Dial-a-Moon'
        )

        print('rendering composite with east sky backdrop …')
        render_phase_closeup(
            nasa_render_path=tmp_moon,
            out_path=str(OUT_PATH),
            output_size=(1920, 1080),
            moon_height_pct=0.88,
            caption=caption,
            east_frame_path=str(EAST_FRAME),
            east_sky_enabled=True,
            east_sky_blur=0,   # auto: output_width / 6 = 320 px
        )
    finally:
        os.unlink(tmp_moon)

    print(f'\ndone → {OUT_PATH}')
    print()
    print('What you should see:')
    print('  • Background: east’s April 29 night sky, blurred to soft atmospheric haze')
    print('    (thin cloud cover visible as a grey-blue gradient, treeline at bottom)')
    print('  • Moon disc filling ~88% of the 1920×1080 frame, pasted sharp on top')
    print('  • Caption at bottom-left with phase / date / witness text')
    print()
    print('In production the procedural disc is replaced by the NASA SVS Dial-a-Moon')
    print('render for that exact UTC hour — same layout, real crater detail.')


if __name__ == '__main__':
    main()